The piano version of this carries labels over each section. Here we have the cricket! Here's the whip-poor-will! Now the smith washes his face! He prays! He striketh his anvil! (This version is a bit abridged, and starts partway through.)

Michaelis also wrote The Turkish Patrol, equally silly but unlabeled.

The "triangle" you hear is probably an anvil, or is supposed to be one. It's labeled as such in the piano version. They were probably very proud of their anvil.